A tire is produced by preparing an unvulcanized green tire first and then by vulcanizing the green tire while molding the green tire into a predetermined shape by using a tire vulcanization device.
A tire vulcanization device known in the art includes a vulcanization mold used to mold a green tire into a predetermined shape, which includes sectors for forming a tread portion of a tire, and a pair of upper and lower side plates for forming a sidewall portion of the tire.
While the tire vulcanization device is in a mold open state in which the upper side plate and the sectors are spaced apart from the lower side plate, a green tire is set on the lower side plate. Then, by moving down the upper side plate and moving the sectors inward in a tire radial direction, the tire vulcanization device is changed to a mold close state in which the upper side plate and the sectors are in close proximity to the lower side plate. The multiple sectors are divided in a circumferential direction. The sectors are radially separated in the mold open state whereas the sectors gather together and form an annular shape in the mold close state.
A pattern of various rugged shapes is provided to an outer surface of the tread portion and the sidewall portion. A rugged shape continuing from the tread portion to the sidewall portion is provided in some cases to make a design of the tire more sophisticated. In a case where such a pattern is provided, when mold parting lines formed by the sectors and the side plates are disposed to the sidewall portion, rubber squeezed out from the mold parting lines may possibly set at an easy-to-notice spot in outward appearance.
Meanwhile, a technique to dispose mold parting lines formed by the sectors and the side plates to the tread portion is known in the art (see Patent Literatures 1 and 2). With this technique, rubber squeezed out in the easy-to-notice sidewall portion can be limited.